12 



Coast marks, consisting of half-inch holes, three inches deep, were 

 bored in the chalk on the line of marine erosion. 







That with the circle round it is the test hole, the others are only 

 guide marks. 



The erosion of the chalk is surprisingly slow, only about half an 

 inch in a year, some of the marks of 1890 were intact in 1893. Large 

 blocks are, however, torn out from time to time, and especially where 

 the land springs undermine the cliffs, or where the shingle is 

 intercepted by piers on groynes to the westward. 



Raised Beach. — Captain McDakin read a Paper on the evidence 

 of a Raised Beach occuring at an elevation of 140 feet above the sea 

 near the second milestone from Dover on the London Road. At this 

 place the cutting of the Deal and Dover railway exposes a section of 

 subangular flint mixed with subspherical chalk pebbles. This deposit 

 is being worked in a gravel pit near the same spot. The elevation of 

 T40 feet corresponds with the raised beaches on the South Downs near 

 Arundel and Chichester. As similar gravels are now being formed both 

 to the east and west of Dover, the author concludes that these pebbles 

 are evidence of the same action and lliat the chalk rubble was rounded 

 by the waves of a quiet inlet of the sea in recent •j;eological times. 

 7'hese chalk pebbles are found in spots round the coast, occasionally 

 reached by the waves at spring-tides, but where the action on the 

 chalk is repeated at every tide the chalk is entirely worn away and only 

 the harder materials arc left, as shingle, which on the coast of Kent is 

 almost entirely flint. 



